Vanda Pharmaceuticals Announces Initiation of The Thetis Study, a Clinical Trial of NEREUS™ for the Prevention of Vomiting Induced by GLP-1 Receptor Agonists

Rhea-AI Summary

Vanda Pharmaceuticals (Nasdaq: VNDA) initiated Thetis, a multicenter, randomized, double-blind Phase 2 trial of NEREUS™ (tradipitant) to prevent vomiting in patients started on high-dose GLP-1 receptor agonists. The company expects topline results by Q4 2026.

Prior Phase 2 data showed vomiting in 29.3% of tradipitant-treated participants versus 58.6% on placebo (p=0.0016), a 50% relative reduction; a key secondary endpoint also favored tradipitant (22.4% vs 48.3%, p=0.0039).

Positive

• Phase 2 success: 50% relative reduction in vomiting (tradipitant vs placebo)
• Topline timeline: Thetis results expected by Q4 2026
• Regulatory foothold: NEREUS approved for motion-induced vomiting

Negative

• Residual vomiting: 29.3% of tradipitant-treated participants still vomited
• NDA uncertainty: Additional study data may be required before NDA submission

News Market Reaction – VNDA

+0.55%

+0.55% Session close to close

In the Apr 9 session, VNDA gained 0.55%, reflecting a mild positive market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement advances Vanda’s NEREUS™ program into Thetis, a randomized, double‑blind, placebo‑...

Analysis

This announcement advances Vanda’s NEREUS™ program into Thetis, a randomized, double‑blind, placebo‑controlled study targeting GLP‑1‑induced vomiting, building on prior Phase 2 data with a 50% relative reduction in vomiting and strong p‑values (p=0.0016, p=0.0039). Investors may track Q4 2026 topline timing, any additional study requirements before NDA, the recently filed $200,000,000 shelf, and how this program complements Vanda’s broader pipeline.

Key Figures

Wegovy dose: 1 mg injection Titration period: 9 weeks Vomiting rate – tradipitant: 29.3% (17/58) +5 more

8 metrics

Wegovy dose 1 mg injection High-dose Wegovy used in Phase 2 study without 9-week titration

Titration period 9 weeks Time normally needed to reach 1 mg Wegovy dose

Vomiting rate – tradipitant 29.3% (17/58) Phase 2 primary endpoint in GLP‑1 vomiting prevention study

Vomiting rate – placebo 58.6% (34/58) Phase 2 comparator arm in GLP‑1 vomiting prevention study

Primary endpoint p‑value p=0.0016 Statistical significance for reduction in vomiting vs placebo

Vomiting + nausea – tradipitant 22.4% (13/58) Key secondary endpoint in Phase 2 GLP‑1 study

Vomiting + nausea – placebo 48.3% (28/58) Secondary endpoint placebo arm in Phase 2 GLP‑1 study

Topline timing Q4 2026 Expected timing for Thetis study topline results

Previous Clinical trial Reports

5 past events · Latest: Jan 08 (Negative)

Same Type Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Jan 08	FDA decision letter	Negative	-14.1%	FDA concluded HETLIOZ® jet lag sNDA cannot be approved in current form.
Nov 05	Conference participation	Neutral	-0.7%	Company participation and presentation at Stifel 2025 Healthcare Conference.
Oct 08	Brand partnership	Positive	+2.7%	Multi‑year Founding Partner deal with Monumental Sports & Entertainment for arena branding.
Oct 01	FDA dispute framework	Positive	+1.2%	Collaborative framework with FDA to resolve multiple disputes on HETLIOZ® and tradipitant.
Sep 25	Insomnia trial data	Positive	-1.4%	Publication of positive HETLIOZ® insomnia trial results in PLOS One journal.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

Clinical-trial-tagged headlines for VNDA have shown mixed reactions, with an average move of -2.45% and both strong selloffs on negative FDA decisions and modest gains on collaborative/regulatory progress.

Recent Company History

Recent clinical‑trial‑tagged news for Vanda spans regulatory friction and progress with the FDA as well as broader visibility efforts. In Jan 2026, an FDA letter stating HETLIOZ® “cannot be approved in its current form” saw shares fall 14.05%. Earlier, a collaborative framework with the FDA on HETLIOZ® and tradipitant in Oct 2025 and positive insomnia trial data drove smaller moves. Against this backdrop, the NEREUS™ GLP‑1 vomiting prevention program extends Vanda’s clinical footprint beyond sleep and jet lag.

Key Terms

glucagon-like peptide-1 (glp-1) receptor agonist therapies, semaglutide, tirzepatide, randomized, double-blind, placebo-controlled, +4 more

8 terms

glucagon-like peptide-1 (glp-1) receptor agonist therapies medical

"patients receiving glucagon-like peptide-1 (GLP-1) receptor agonist therapies."

A class of prescription medicines that mimic a naturally occurring gut hormone to lower blood sugar and often reduce appetite and body weight; they act like a thermostat reset for the body’s glucose and hunger signals. Investors watch them because they can drive large, recurring drug sales, reshape markets for diabetes and obesity treatments, and face regulatory decisions, patent timelines and competition that directly affect company revenue and valuation.

semaglutide medical

"GLP-1 receptor agonists, including semaglutide and tirzepatide, have transformed"

Semaglutide is a medication originally developed to help manage blood sugar levels in people with diabetes, but it also promotes weight loss. It works by mimicking a natural hormone that helps control appetite and insulin release. For investors, its potential to influence healthcare and weight management markets makes it a significant product in the pharmaceutical industry.

tirzepatide medical

"GLP-1 receptor agonists, including semaglutide and tirzepatide, have transformed"

Tirzepatide is a prescription medicine that helps lower blood sugar and reduce appetite by activating two hormones that regulate insulin and hunger; think of it as a two-in-one switch that calms the body’s sugar spikes and decreases cravings. Investors watch it because regulatory approvals, clinical results, pricing and patient demand determine sales potential and competitive impact on companies in diabetes and obesity treatment markets.

randomized, double-blind, placebo-controlled technical

"a multicenter, randomized, double-blind, placebo-controlled trial that will evaluate"

A "randomized, double-blind, placebo-controlled" process is a method used to test the effectiveness of a new treatment or intervention. Participants are randomly assigned to different groups, with one receiving the real treatment and the other a fake version, called a placebo. Neither the participants nor the researchers know who is receiving which, which helps ensure unbiased results. For investors, this rigorous approach increases confidence that the findings are accurate and not influenced by guesswork or bias.

phase 2 study medical

"The Phase 2 study, as previously announced in Vanda's press release"

A phase 2 study is a mid-stage clinical trial that tests whether an experimental drug or treatment actually works for the intended condition and continues to check safety in a larger group of patients than early trials. Think of it as a focused pilot test before a full market launch; positive or negative results strongly affect a drug’s chances of approval, the remaining development time and costs, and therefore an investment’s risk and potential value.

p=0.0016 technical

"experiencing vomiting compared to 58.6% on placebo (34/58) (p=0.0016)"

p=0.0016 indicates that, if there were actually no real effect or difference, the observed result (or one more extreme) would occur by random chance about 0.16% of the time. For investors, that very low probability signals strong statistical evidence behind a claim or study finding, much like getting an unusually rare run of heads when flipping a coin repeatedly; such a result makes the claim more credible and can affect market confidence and valuation.

p=0.0039 technical

"22.4% in the tradipitant group (13/58) versus 48.3% on placebo (28/58) (p=0.0039)"

p=0.0039 is a statistical number that expresses how likely a reported result would occur just by random chance; a value this small (about 0.39%) means the observed effect is unlikely to be a fluke. For investors, a low p-value strengthens confidence that a study or test result reflects a real pattern rather than randomness, but it does not measure how large or economically important that effect is.

new drug application (nda) regulatory

"may be required prior to approval of a New Drug Application (NDA)."

A new drug application (NDA) is a formal request submitted to regulatory authorities to gain approval for a new medication to be sold and used by the public. It is a comprehensive review process that examines the drug’s safety, effectiveness, and manufacturing quality. For investors, an NDA approval can signal a potential breakthrough product and influence a company's stock value.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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WASHINGTON, April 8, 2026 /PRNewswire/ -- Vanda Pharmaceuticals Inc. (Vanda) (Nasdaq: VNDA) today announced the initiation of Thetis, a clinical trial evaluating NEREUS™ (tradipitant) for the prevention of vomiting in patients receiving glucagon-like peptide-1 (GLP-1) receptor agonist therapies. NEREUS™ was recently approved for the prevention of vomiting induced by motion.¹

GLP-1 receptor agonists, including semaglutide and tirzepatide, have transformed the treatment of type 2 diabetes and obesity. However, gastrointestinal side effects, particularly nausea and vomiting, remain a significant challenge for many patients and are a leading cause of treatment discontinuation or dose reduction. Recent studies and approvals in the GLP-1 space further underscore this. Last month, a "high dose" of Wegovy was approved by the U.S. Food and Drug Administration (FDA) on the basis of providing additional weight-loss benefits, yet it comes with the tradeoff that the top two reported adverse effects of nausea and vomiting for this high dose are of increased frequency compared to the previously approved Wegovy maximum dose.²

"GLP-1 receptor agonists offer significant benefits, but vomiting and nausea can severely impact patient adherence and quality of life," said Mihael H. Polymeropoulos, M.D., President CEO and Chairman of the Board of Vanda Pharmaceuticals. "NEREUS™ has demonstrated potent antiemetic effects in prior clinical studies. We are excited to advance this program, which has the potential to improve tolerability and allow more patients to fully benefit from these important therapies."

The Thetis study is a multicenter, randomized, double-blind, placebo-controlled trial that will evaluate the efficacy and safety of oral tradipitant in patients initiated at a high dose of a GLP-1 receptor agonist. The primary endpoint is the proportion of patients free from vomiting episodes during the treatment period.

The Phase 2 study, as previously announced in Vanda's press release dated November 15, 2025, was similar in design where patients were pre-treated with either tradipitant or placebo before administering a 1 mg injection of Wegovy^®, a dose that normally takes 9 weeks of titration to reach. The phase 2 study succeeded and met its primary endpoint, with only 29.3% of tradipitant-treated participants (17/58) experiencing vomiting compared to 58.6% on placebo (34/58) (p=0.0016), representing a 50% relative reduction. The study also met the key secondary endpoint of the proportion of participants with vomiting and significant nausea at 22.4% in the tradipitant group (13/58) versus 48.3% on placebo (28/58) (p=0.0039).³

Vanda expects topline results from the Thetis study by Q4 2026. Following completion of the Thetis study, additional study data may be required prior to approval of a New Drug Application (NDA).

References

1. See full U.S. NEREUS Prescribing Information, available at: www.nereus.us.
2. See full U.S. Wegovy Prescribing Information, available at: https://www.novo-pi.com/wegovy.pdf.
3. See Vanda Pharmaceuticals Reports Positive Results for Tradipitant in Preventing GLP-1 Induced Nausea and Vomiting, available at: https://www.prnewswire.com/news-releases/vanda-pharmaceuticals-reports-positive-results-for-tradipitant-in-preventing-glp-1-induced-nausea-and-vomiting-302617739.html.

About NEREUS™

NEREUS™ (tradipitant) is a neurokinin-1 receptor antagonist licensed by Vanda from Eli Lilly and Company. NEREUS™ is approved for the acute prevention of vomiting induced by motion in adults, and is currently in clinical development for a variety of indications, including gastroparesis and the prevention of nausea and vomiting induced by GLP-1 receptor agonists. Full NEREUS™ Prescribing Information can be found at: https://www.nereus.us.

About Vanda Pharmaceuticals Inc.

Vanda is a leading global biopharmaceutical company focused on the development and commercialization of innovative therapies to address high unmet medical needs and improve the lives of patients. For more on Vanda Pharmaceuticals Inc., please visit www.vandapharma.com and follow us on X @vandapharma.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

Various statements in this press release, including, but not limited to, statements regarding the design, objectives and potential outcomes of the Thetis clinical trial; the potential benefits, effectiveness and safety of NEREUS™ (tradipitant) for the prevention of vomiting in patients receiving GLP‑1 receptor agonist therapies; the significance of results from prior clinical studies; the expected timing of topline results from the Thetis study; and the risk that additional study data may be required prior to approval of an NDA, are "forward‑looking statements" within the meaning of the securities laws. All statements other than statements of historical fact are statements that could be deemed forward‑looking statements. Forward‑looking statements are based on current expectations and assumptions that involve risks, changes in circumstances and uncertainties. Important factors that could cause actual results to differ materially from those reflected in Vanda's forward-looking statements include, among others, risks inherent in clinical development, including the risk that the Thetis trial may not demonstrate efficacy or safety consistent with prior studies, may not meet its primary or secondary endpoints, or may experience delays; variability in patient response to therapy; regulatory considerations affecting the development of NEREUS™ for additional indications; and the risk that additional study data may be required prior to approval of an NDA. Therefore, no assurance can be given that the results or developments anticipated by Vanda will be realized or, even if substantially realized, that they will have the expected consequences to, or effects on, Vanda. Forward‑looking statements in this press release should be evaluated together with the risks and uncertainties described in the sections titled "Cautionary Note Regarding Forward‑Looking Statements," "Risk Factors," and "Management's Discussion and Analysis of Financial Condition and Results of Operations" in Vanda's most recent Annual Report on Form 10‑K, as updated by Vanda's subsequent Quarterly Reports on Form 10‑Q, Current Reports on Form 8‑K, and other filings with the U.S. Securities and Exchange Commission, which are available at www.sec.gov.

All forward‑looking statements attributable to Vanda or any person acting on its behalf are expressly qualified in their entirety by the cautionary statements set forth herein. Vanda cautions investors not to place undue reliance on forward‑looking statements. The information contained in this press release is provided as of the date hereof, and Vanda undertakes no obligation, and expressly disclaims any obligation, to update or revise any forward‑looking statements, whether as a result of new information, future events, or otherwise, except as required by law.

Corporate Contact:

Kevin Moran
Senior Vice President, Chief Financial Officer and Treasurer
Vanda Pharmaceuticals Inc.
202-734-3400
pr@vandapharma.com

Jim Golden / Jack Kelleher / Dan Moore
Collected Strategies
VANDA-CS@collectedstrategies.com

Follow us on X @vandapharma

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SOURCE Vanda Pharmaceuticals Inc.

FAQ

What is the purpose of Vanda's Thetis study (VNDA) launched April 8, 2026?

Thetis evaluates whether oral tradipitant prevents vomiting in patients starting high-dose GLP-1 therapies. According to Vanda, it is a randomized, double-blind, placebo-controlled Phase 2 trial with a primary endpoint of proportion free from vomiting.

When does Vanda (VNDA) expect topline results from the Thetis trial?

Vanda expects topline Thetis results by Q4 2026. According to Vanda, the company set this timeline when announcing initiation of the multicenter Phase 2 study on April 8, 2026.

What were the key Phase 2 tradipitant results Vanda reported earlier for GLP-1 induced vomiting?

Earlier Phase 2 showed 29.3% vomited on tradipitant versus 58.6% on placebo (p=0.0016). According to Vanda, this represents a 50% relative reduction and met the primary endpoint.

Does Vanda (VNDA) already have any approval for NEREUS (tradipitant)?

Yes. According to Vanda, NEREUS is approved for prevention of motion-induced vomiting in the U.S., providing an existing regulatory precedent for its antiemetic use.

Will Vanda (VNDA) be able to file an NDA after Thetis completion?

Not guaranteed; additional studies may be required before filing an NDA. According to Vanda, completion of Thetis may not be sufficient and further data could be requested by regulators.